1. Field of the Invention
This invention relates to a scene brightness measuring system to be used for a photographic camera, motion picture camera, television camera and the like, and more particularly to a method of measuring the scene brightness by calculating the scene brightness from measured values of the maximum brightness, the minimum brightness and other brightness at various points of the scene.
2. Description of the Prior Art
In the light measuring method for measuring the scene brightness adopted in a photographic camera, there have been generally known and widely used three types of light measuring method. One is an average light measuring method in which one or two photosensors are used for measuring the brightness of the whole scene, another is a partial light measuring method in which the brightness of only a part of the scene is measured, and the third is a center-weighted light measuring method in which the central portion of the scene is weighted in the light measurement.
Recently, it has been proposed to use a number of photosensors to measure the brightness at various points of the scene and obtain the maximum and minimum values of the brightness, and determine the scene brightness using one of extreme values according to the brightness distribution of the scene or using a middle value between the two extreme values. These methods are intended to measure the brightness of the principal subject matter as accurately as possible to obtain an appropriate exposure of the principal subject matter. These methods, however, have a drawback that the principal subject matter gets under-exposure in case where the scene has a backlight or over-exposure in case where the principal subject matter is a spotlighted matter in a dark background.